I have the below code. I cannot figure out how to obtain the real and imaginary parts of the symbolic polynomial (I have already solved the complete problem in standard Matlab, trying to learn the Symbolic Toolbox). My code is:

`polynomial = [1 10 45 105 105]; % This polynomial is the Bessel Filter `

% polynomial computed above, and changes with the order of the filter.

p = poly2sym(polynomial, s)pw = subs(p, 1*j*w)% attempt from Walter Roberson's comment at:

% https://www.mathworks.com/matlabcentral/answers/

% 465739-real-and-imaginary-part-of-this-function-please

real_pw = simplify( rewrite(real(pw), 'exp') )imag_pw = simplify( rewrite(imag(pw), 'exp') )% NOT WORKING FOR ME

% Assuming I can get the above done, my next steps would be to convert the

% below (from standard Matlab) to symbolic. Any help with the below would

% also be appreciated.

sq_real = conv(real_pw, real_pw);sq_imag = conv(imag_pw, imag_pw);sq_denom = sq_real + sq_imag;

The above code gives me:

real_pw =

10*imag(w^3) – 45*real(w^2) + real(w^4) – 105*imag(w) + 105

imag_pw =

imag(w^4) – 45*imag(w^2) – 10*real(w^3) + 105*real(w)

Instead, I am expecting something like (obtained from my working plain Matlab code):

real_poly = 1 0 -45 0 105

imag_poly = 0 -10 0 105 0

Any help you can provide is appreciated!

## Best Answer